The present invention relates to a contact simulation method for a rubber material capable of simulating a contact state of a rubber material with a surface of an arbitrary material.
In order to analyze a contact state of a rubber material with a surface of an arbitrary material, there has been proposed a simulation method in which, according to a finite element method, the rubber material and a contact zone of the material including the contact surface are respectively modeled by a finite number of elements on which material characteristics are defined, and the contact state is simulated by the use of such rubber model and contact zone model.
In this method, since the adjacent elements are linked to each other, if the tensile deformation of the rubber model during the deformation calculation becomes very large for example exceeds 100%, there is a possibility that the elements are broken and a calculation failure is caused.
Therefore, in the simulation method based on the finite element method, there is a problem such that it is difficult to fully or accurately analyze the contact state of a rubber material subjected to a large deformation.
In the following non-patent document 1, there has been proposed a simulation method based on molecular dynamics in which interactions between molecular models are defined and intermolecular contact is analyzed. The above-mentioned calculation failure does not occur in this method.
In this method based on molecular dynamics, contacts at the micro-level or nano-level occurring between molecules can be analyzed, but it is realistically impossible to use this method to analyze contacts at the macro-level occurring between a rubber material and a surface of another object.
In the following non-patent document 2 or non-patent document 3, there has been proposed a simulation method based on the particle method in which an analysis object is modeled by a finite number of particles on which Newton's motion equations are respectively defined instead of the above-explained interactions therebetween.
In these methods, however, the resilience of the rubber material is not defined in the motion equation, therefore, if the deformation of the rubber model is increased during deformation calculation, the rubber model can not return to its former shape.
Thus, in the methods based on such particle method, there is a problem such that the contact state of the rubber material subjected to a relatively large deformation can not be analyzed.
[Non-Patent Document 1]
    H. Morita, T. Ikehara, T. Nishi, M. Doi, Polymer J. 36, 265 (2004) polymer journal 36, 265 2004[Non-Patent Document 2]    Yoichi KAWASHIMA and Yuzuru SAKAI “Large Deformation Analysis of Hyperelastic Materials using SPH Method” e-Journal of Soft Materials Vol. 3, pp. 22-28 (2007)[Non-Patent Document 3]    Yuzuru SAKAI, “Fundamentals and Applications of SPH method”, [online], CAE social gathering, [searched on Oct. 1, 2012], <Internet URL: http://www.cae21.org/kaisekijuku2006/SPH.pdf>